RVO Horizon® 80 ED Doublet Refractor OTA

The brand new RVO Horizon® 80mm ED Doublet refractor has joined the RVO Horizon family! These superior quality refractors deliver breathtaking images thanks to it's FPL-53 glass which will deliver high contrast, sharp views each and every time! This amazing new telescope system is backed up by matching accessories such as a 1.0x field flattener, 0.8x reducer flattener and the Horizon 50mm guidescope.

Features:

- Fresh & Unique Looking Design
- High Quality FPL-53 ED Optics
- Zygo Optical Test With Every Scope
- Minimum 0.95 Strehl Ratio
- Collimatable Cell
- Heavy Duty Rack & Pinion 2" Focuser With 1.25" Adaptor
- 10:1 Microfocuser
- Long Slotted Dovetail Bar With Riser Blocks For Easy Balancing
- High Quality Tube Rings
- Retractable Dew Shield
- Top Vixen Bar For Mounting Horizon® Guide & Other Accessories
- Aluminium Flight Case Included

This amazing image of the Horsehead Nebula was taken with our Horizon 72 ED. The same glass quality is used on our full Horizon range. The image below was taken with the ZWO 533MC Pro with the Optolong L-eXtreme filter. 3 hours worth of subs, 30 darks, 30 flats and 30 dark flats. 

We are incredibly proud and excited to announce another high quality ED refractor. A beautifully designed 80mm ED refractor capable of visual and imaging, both for planetary and deep sky. The longer focal length compared to the Horizon 72 ensures a larger reach whilst ensuring wide field for DSO work. The refractor is designed in our striking colours to match the other Horizon refractors. We have developed and manufactured this scope to meet all the needs of the modern day imager. The scope itself has high quality FPL-53 ED glass complete with matching zygo report so you can see for yourself, the quality of the lens you are purchasing. Not only that, we guarantee that all of our telescopes have a minimum 0.95 Strehl ratio for the highest quality images every time. In addition to this, we optically test each and every telescope that we sell to ensure you receive a perfect telescope each and every time. The scope is complimented with an aluminium lockable hard case for transport and storage. All featuring the brand new RVO Horizon® logo.

This telescope features a high quality 2" dual speed rack and pinion focuser. All CNC machined for a superb build quality and ultimate hold when accessories such as flatteners and CMOS/SLR cameras are attached. The 10:1 microfocuser ensures you can achieve the perfect focus every time. The focuser also features an indexed drawtube for precise and fast repositioning of targets. It also includes a focus lock so you can't accidentally alter focus when imaging.

Unlike most imaging refractors, this telescope has been designed to overcome all the issues with other telescopes. The main issue is balancing when you start to add heavy accessories and cameras. The Horizon® 80 ED comes as standard with a 30cm slotted vixen style dovetail bar, plus riser blocks fitted to the rings to ensure it misses the focus lock knob. Simply add your accessories, then slide your Horizon® OTA higher up the dovetail saddle and you are balanced. No additional accessories are required. The OTA kit also comes with a short vixen style bar to sit on top of the tube rings for adding our superb Horizon® Guide guidescope or other accessories with a vixen style clamp.

The Horizon® 80ED comes as standard with a 2" visual back, plus 2" - 1.25" adaptor. All connections feature non-marring compression rings for security and ease of use. Both 2" and 1.25" diagonals are fully compatible with the Horizon® 80. The long drawtube ensures achievable focus when using a wide range of diagonals and eyepieces. The OTA is also fitted with a universal synta style base for attaching a wide range of finderscopes and guidescopes. If you are looking for a lightweight alternative to the Horizon® Guide, then look at our 50mm mini Horizon guide scope, which is fully compatible. This will keep the weight down on the system which is paramount if you are using smaller, lightweight equatorial mounts.

An in house Zygo interferometer test & report is supplied with the Horizon 80mm. 

The interferometer is essentially a measuring instrument. Within the interferometer is a calibrated laser that is pointed through the optical test surface, then onto a high quality reference sphere, then back through the test subject then to an internal camera which gives us the measurement on the screen. From this, we can adjust the position of the test optic and the reference sphere to obtain a perfectly calibrated system. The more central the laser to the test optic and then on return, the better and more accurate reading and measurement we can take. This takes a lot of adjustment to get the best results from the optical surface. Once the measurement has been taken, we are provided with a series of results that show the optical quality of the surface plus other information. We will aim to provide 0.95 Strehl or higher. 

Accessories (optional extras):

We have also developed a range of matching accessories to compliment the Horizon® 80ED. The first important accessory for imagers is the field flattener. This has been specially designed to work perfectly and compliment the Horizon® 80ED optics. There are 2 versions available for the 80mm ED. A 1.0x field flattener with no reduction or a 0.8x reducer/flattener. By using our field flatteners and reducers, you can rest assured you will have a lovely flat field each and every time. The field flattener also features a rotator with locking knob so you can ensure your camera is at the right orientation each and every time. A comprehensive, easy to follow instruction sheet is included on how to fit the flattener to your Horizon® 80 ED. The backfocus required to your sensor is 55mm.

The other fantastic accessory is the all new RVO Horizon® Guide. This is a high quality 50mm finder/guidescope that comes complete with a vixen clamp, 24mm illuminated crosshair eyepiece, 1.25" & T2 connections, ring system with 6 point delrin tipped adjusters complete with a high quality indexed helical focuser.

The retractable dew shield will keep a certain amount of dew at bay, but some nights will require a heater system to fully elimiate dew. Our RVO bands are perfect for the job. These high quality made bands simply wrap around the outer edge of the OTA close to the front element and gently heat the glass up just past the dew point. The bands have an elasticated velcro strap for a snug fit. All complete with either an integrated controller to work with any 12v power source, or an RCA jack for use with all dew controllers.

Specifications:

- Air Spaced 80mm ED Doublet Design
- 560mm Focal Length
- F/7 Focal Ratio
- Weight (OTA Only) 3.45kg
- Retracted Length 425mm
- CNC Machined Dual Speed Rack & Pinion Focuser
- Long 30cm Dovetail Bar With 1/4" Thread
- Retractable Dew Shield
- Aluminium Cap
- 2" - 1.25" Reducer With Non-marring Compression Rings
- Lightweight Aluminium CNC Machined Tube
- Collimatable Cell
- 10:1 Microfocuser

Our RVO Horizon® 80 ED OTA goes perfectly with a wide range of equatorial style systems. The included bar makes it compatible with all standard equatorial mounts with a vixen style saddle.

Some items that are showing as in stock are in stock at our holding warehouses, not at the shop. To double check the stock levels at the shop, please contact us on 01909774369 or sales@rothervalleyoptics.co.uk.

The delivery times for most items is 1 - 2 days but again, please double check stock levels on important orders before placing an order via the website.

The delivery costs for courier next day are for mainland UK only. If you live in the Scottish Highlands/Islands, Channel Islands or Northern Ireland, then a shipping surchage will apply. please contact us for prices. Smaller items can still go 1st class via Royal Mail.

Please note that if you are wanting to take advantage of our Saturday and Sunday timed services or next day pre 12 or pre 10:30 services, you MUST check that the stock is here at the shop before placing orders. Also, orders using the Saturday and Sunday services must be placed before 1pm the previous working day. Also, please remember to check that the stock is here at the shop before placing orders. If the stock is not at the shop, we won't be able to ship on any of the timed services. 

Please note International customers will need to contact us for a shipping price prior to ordering via the website. We don't ship all items internationally. It is at our discretion what we ship outside of the UK. This all depends on the size and weight of the items. Please get in touch with us for any postage costs. Please note we do NOT ship telescopes or heavy items outside of the UK. This is due to massive postage costs and problems regarding returns.

If you have any questions regarding stock levels or delivery, please get in touch.

Zygo Interferometer Testing For ED Refractor Telescopes!

We are extremely pleased to announce our Zygo Interferometer is now installed and ready for use! Our experienced staff can test refractor lenses up to 120mm aperture and provide a comprehensive 2 page report showing the optical quality and Strehl ratio, plus much more information. We are using the very latest Zygo MX software to provide a more detailed report compared to other standard reports.

The interferometer is essentially a measuring instrument. Within the interferometer is a calibrated laser that is pointed through the optical test surface, then onto a high quality reference sphere, then back through the test subject then to an internal camera which gives us the measurement on the screen. From this, we can adjust the position of the test optic and the reference sphere to obtain a perfectly calibrated system. The more central the laser to the test optic and then on return, the better and more accurate reading and measurement we can take. This takes a lot of adjustment to get the best results from the optical surface. Once the measurement has been taken, we are provided with a series of results that show the optical quality of the surface plus other information. Continue reading for an explanation of the individual values and you can also see a test report that was done on one of our RVO Horizon 60 OTAs. 

We are offering certain telescopes with a Zygo test at an extra cost. Mainly ED doublets and triplets. All available telescopes with a Zygo test report are listed here. Just select Zygo Test Report from the drop down box at the top of the listing and we will test the optics in house and provide a full 2 page report with your scope. This will show you the optical quality of your telescope optics. We can also offer this service on your refractor telescope. Please get in touch for more details about this. 

At Rother Valley Optics, one thing we pride ourselves on is customer service and quality of our equipment. When we test your telescope, we will ensure that it is of the highest quality otherwise, we will reject the scope under our strict quality control and test another model for your peace of mind. One of the main values to look at when testing a refractor is the Strehl ratio. The higher this number, the higher quality lens you have. At Rother Valley Optics, we will guarantee the highest possible Strehl ratio for your telescope.  We will aim to provide 0.95 Strehl or higher on Takahashi, RVO Horizon, William Optics and many more! Generally, the higher the Strehl ratio, the lower the Astigmatism and Coma meaning a better image quality from your instrument. 

Other measurements such as the PV and RMS are important too. With these measurements, the lower the number the better as it shows less curvature on the lens. The flatter an optical lens, the better it will perform. The PV rating (Peak To Valley) is a measurement from the highest point (Peak) to the lowest point (Valley). From this we get the RMS (Root, Mean, Square). This is a similar figure to the PV and measured exactly the same way. The RMS is basically an average height difference from the PV so again, the lower the better. As you can see form the example below, we measured an RMS of just 0.027 wave which is a very good value.

We also measure the Power with our systems which is essentially the error from the reference sphere to the test optic. The reference sphere we use on our system is a very high quality sphere so the closer to zero the Power, the less error between the 2 elements thus ensuring a higher quality optical surface. 

You will also see some more values such as Astigmatism and Coma. Again, these are measured by the interferometer when we take measurements of the optical surface after adjustment. These are values which ideally would be at 0 but as our test optics are all curved lenses, there will always be astigmatism and coma present. The lower the number, the less of these aberations you will effectively see but with most refractors, you can buy field flatteners which will compensate for the coma anyway. The astigmatisms value is explaining the error between the symmetrical curvature of the lens. Basically, no lens will be perfectly symmetrical, the lower the astigmatism, the more symmetrical the lens surface is. 

Once the Zygo test report has been completed, the optical alignment is thoroughly tested and tuned to ensure they are spot on before they leave us. 

All available telescopes are on the website at the link below and ones we've tested already that are available straight away are also listed.

https://www.rothervalleyoptics.co.uk/zygo-tested-refractors.html

Here is an example of the test what we provide. This was a test on one of our Horizon 60 ED OTA's.

For any questions about this amazing new service, please either call 01909774369 or email sales@rothervalleyoptics.co.uk.

Are you interested in this product but would like to speak to someone with some more information? Simply fill in the form below and we will get back to you as soon as we can!

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